Internal combustion engines such as used in automobiles are typically of the reciprocating type in which a piston oscillating in a cylinder drives a crankshaft via a connecting rod. There are numerous disadvantages in the conventional reciprocating engine design, which disadvantages in large stem from the lack of mechanical advantage that the connecting rod has to transfer power to the crankshaft over a complete stroke.
A connecting rod achieves its maximum mechanical transfer at approximately 60 degrees After Top Dead Centre (ATDC). The engine described in WO 97/04225 addresses this lack of mechanical transfer by spreading the maximum mechanical transfer over a greater range of degrees of rotation. This has resulted in high torque over a large RPM range providing a very flat torque curve.
During a project aimed at developing the engine described in WO 97/04225 for aircraft use, it was found that on a counter rotating three lobed drive cam design (trilobate) that the cam lobes become in phase every 60 degrees of rotation. This feature offers the potential for the incorporation of two sets of piston assemblies per one counter rotating dual trilobate assembly in each module of the engine.
It is an object of the present invention to improve on the engine the subject of WO 97/04225 by exploiting the feature referred to in the previous paragraph.